Does the AVNeo valve reduce wall stress on the aortic wall? A cardiac magnetic resonance analysis with 4D-flow for the evaluation of aortic valve replacement with the Ozaki technique

Background: Aortic valve neocuspidalization aims to replace the three aortic cusps with autologous pericardium pre-treated with glutaraldehyde and is a surgical alternative to the classical aortic valve replacement.Image-based patient-specific computational fluid dynamics allows the derivation of shear stress on the aortic wall (WSS). Previous studies support a potential link between increased WSS and histological alterations of the aortic wall.The aim of this study is to compare the WSS of the ascending aorta in patients undergoing aortic valve neocuspidalization vs aortic valve replacement with biological prostheses. Methods: This is a prospective nonrandomized clinical trial. Each patient underwent 4D-flow cardiac magnetic resonance scan after surgery, which informed patient-specific computational fluid dynamics models to evaluate WSS at the ascending aortic wall. The adjusted variables were calculated by summing the residuals obtained from a multivariate linear model (with ejection fraction and left ventricle outflow tract-aorta angle as covariates) to the mean of the variables. Results: 10 patients treated with aortic valve neocuspidalization were enrolled and compared with 10 aortic valve replacement patients. Aortic valve neocuspidalization group showed a significantly lower WSS in the outer curvature segments of the proximal and distal ascending aorta as compared to aortic valve replacement patients (p 0.0179 and 0.0412, respectively). WSS levels remained significantly lower along the outer curvature of the proximal aorta in the aortic valve neocuspidalization population, even after adjusting the WSS for the ejection fraction and the left ventricle outflow tract-aorta angle (2.44 Pa(2.17-3.01) vs 1.94 Pa(1.72-2.01), p 0.02). Conclusions: Aortic valve neocuspidalization hemodynamical features are potentially associated with a lower WSS in the ascending aorta as compared to commercially available bioprosthetic valves.